Palmar hyperhidrosis is a common disorder among orientals. A new therapeutic technique for this disorder has been designed by combining a computer compact disc video endoscopic system with a fiberoptic CO2 surgical laser unit. The operation is performed under general anesthesia with alternating one-lung ventilation. There are three important aids in localizing the correct sympathetic segment: 1) direct visualization of its magnified image on the television monitor; 2) identification with an electrode probe palpation at its presumed location; and 3) monitoring the microvasomotor changes on the skin of the finger resulting from electrical stimulation of the sympathetic trunk. Subsequently, the confirmed sympathetic target is vaporized using a low power CO2 laser under direct vision on the television monitor. The laser is delivered to the target by a small optical fiber passing through a throacoscope, which is introduced into the thoracic cavity via the intercostal space between the second and third ribs at the midclavicular line. Fourteen palmar hyperhidrosis patients were successfully treated by this method. No complications, such as Horner's syndrome, bleeding, or intercostal neuralgia, were encountered. Although the number of cases treated was small, and the follow-up period was short, the evidence indicates that a definite sympathectomy on a confirmed segment under magnified vision is possible with this procedure, and could warrant a definite and long-lasting therapeutic effect. Based on our experience, the method is considered a relatively minor and safe procedure, causing minimal discomfort and almost invisible scars. The operation time and hospital stay were remarkably shortened in comparison with other conventional sympathectomy procedures.